X-ray tubes are extremely valuable tools that are used in a wide variety of applications, both industrial and medical. An x-ray tube typically includes a cathode and an anode positioned within an evacuated enclosure. The cathode includes an electron emitter and the anode includes a target surface that is oriented to receive electrons emitted by the electron emitter. During operation of the x-ray tube, an electric current is applied to the electron emitter, which causes electrons to be produced by thermionic emission. The electrons are then accelerated toward the target surface of the anode by applying a high-voltage potential between the cathode assembly and the anode. When the electrons strike the anode target surface, the kinetic energy of the electrons causes the production of x-rays. The x-rays are produced in an omnidirectional fashion where the useful portion ultimately exits the x-ray tube through a window in the x-ray tube, and interacts with a material sample, patient, or other object with the remainder being absorbed by other structures including those whose specific purpose is absorption of x-rays with non-useful trajectories or energies.
During the operation of a typical x-ray tube, electrons are produced at a single energy resulting in x-rays having a distribution of energies with a mean value, herein referred to as x-ray energy. While having one x-ray energy is useful, in some situations it would be desirable to examine a material sample, patient, or other object with x-rays having different x-ray energies. For example, x-rays having multiple energies would be useful in baggage scanning applications where attempts are made to detect materials of different densities.
The subject matter claimed herein is not limited to embodiments that solve any disadvantages or that operate only in environments such as those described above. Rather, this background is only provided to illustrate one exemplary technology area where some embodiments described herein may be practiced.